Click on this to make it larger. Look closely at the moons and planets. You can control the ambient light in the settings. Turn down ambient light and the only light on the planets comes from the stars. If the stars were closer, you would have conflicting sources of light.
Originally the ships were more affected by the stars but we found this to be hard to play even though it was "more realistic". So the ships are self-lit ala Star Trek/Star Wars.
